Apply Shape Animations in Presentations in .NET

What this page is about

Learn how to add, inspect, and customize shape animations, timing, sounds, after-animation behavior, and animated text with Aspose.Slides for .NET.

Overview

Aspose.Slides for .NET represents slide animations as effects in a slide timeline. An effect has a target shape, an animation type and subtype, a trigger, timing settings, and optional properties such as sound or after-animation behavior.

The timeline contains two kinds of sequences:

• The main sequence plays as the slide advances.
• An interactive sequence starts when its trigger shape is clicked.

Because text boxes, pictures, charts, tables, and other slide objects implement IShape, you use the same ISequence.AddEffect method for most slide content. The available effects are listed in the EffectType enumeration.

Add Shape Animations

To add an animation, get the slide’s main sequence and call ISequence.AddEffect with the target shape, effect type, subtype, and trigger. For an effect that starts when another shape is clicked, create an interactive sequence whose trigger is that other shape.

The following example creates both types of animation and saves the result to shape-animations.pptx.

using Aspose.Slides;
using Aspose.Slides.Animation;
using Aspose.Slides.Export;

using var presentation = new Presentation();
var slide = presentation.Slides[0];

var targetShape = slide.Shapes.AddAutoShape(ShapeType.RoundCornerRectangle, 120, 100, 320, 80);
targetShape.TextFrame.Text = "Click to animate this shape";

var mainSequence = slide.Timeline.MainSequence;
var entranceEffect = mainSequence.AddEffect(targetShape, EffectType.Fade, EffectSubtype.None, EffectTriggerType.OnClick);
entranceEffect.Timing.Duration = 1.5f;

var triggerShape = slide.Shapes.AddAutoShape(ShapeType.Bevel, 20, 20, 100, 40);
triggerShape.TextFrame.Text = "Move";

var interactiveSequence = slide.Timeline.InteractiveSequences.Add(triggerShape);
interactiveSequence.AddEffect(targetShape, EffectType.PathFootball, EffectSubtype.None, EffectTriggerType.OnClick);

presentation.Save("shape-animations.pptx", SaveFormat.Pptx);

The trigger controls when an effect starts:

• EffectTriggerType.OnClick waits for a click in the main sequence, or for a click on the trigger shape in an interactive sequence.
• EffectTriggerType.WithPrevious starts with the preceding effect.
• EffectTriggerType.AfterPrevious starts when the preceding effect finishes.

To animate a picture, chart, or another shape type, pass that object to ISequence.AddEffect instead of targetShape. For chart-specific grouping options, see Animated Charts.

Read Shape Animations

Use ISequence.GetEffectsByShape when you know the target shape. To inspect every effect, enumerate the main sequence and every interactive sequence. Enumeration avoids assuming that a sequence contains an effect at index 0.

The following example creates a shape with main-sequence and interactive effects, gets the effects that target the shape, and then enumerates every sequence on the slide.

using System;
using Aspose.Slides;
using Aspose.Slides.Animation;

using var presentation = new Presentation();
var slide = presentation.Slides[0];
var targetShape = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 120, 100, 320, 80);
targetShape.TextFrame.Text = "Animated shape";

var mainSequence = slide.Timeline.MainSequence;
mainSequence.AddEffect(targetShape, EffectType.Fade, EffectSubtype.None, EffectTriggerType.OnClick);

var triggerShape = slide.Shapes.AddAutoShape(ShapeType.Bevel, 20, 20, 100, 40);
triggerShape.TextFrame.Text = "Move";

var interactiveSequence = slide.Timeline.InteractiveSequences.Add(triggerShape);
interactiveSequence.AddEffect(targetShape, EffectType.PathFootball, EffectSubtype.None, EffectTriggerType.OnClick);

var targetEffects = mainSequence.GetEffectsByShape(targetShape);
Console.WriteLine($"The main sequence contains {targetEffects.Length} effect(s) for {targetShape.Name}.");

PrintSequence("Main sequence", mainSequence);

var interactiveIndex = 1;
foreach (var sequence in slide.Timeline.InteractiveSequences)
{
    var triggerName = sequence.TriggerShape == null ? "unknown" : sequence.TriggerShape.Name;
    var sequenceLabel = $"Interactive sequence {interactiveIndex}, trigger: {triggerName}";
    PrintSequence(sequenceLabel, sequence);
    interactiveIndex++;
}

static void PrintSequence(string label, ISequence sequence)
{
    Console.WriteLine($"  {label}: {sequence.Count} effect(s)");

    foreach (var effect in sequence)
    {
        var targetName = effect.TargetShape == null ? "unknown" : effect.TargetShape.Name;
        var effectDescription = $"{effect.Type} {effect.Subtype}; target: {targetName}; trigger: {effect.Timing.TriggerType}";
        Console.WriteLine($"    {effectDescription}");
    }
}

If you only need the effects for one shape, first identify the shape by name, placeholder type, or another stable property; then call ISequence.GetEffectsByShape. Do not assume that IShapeCollection.Item at index 0 is always the intended object.

Work with Inherited Placeholder Effects

A placeholder on a normal slide can inherit animation behavior from the corresponding placeholder on its layout slide and master slide. IShape.GetBasePlaceholder returns that parent placeholder, or null when no parent exists.

In the following example presentation, the footer has Random Bars on the normal slide, Split on the layout slide, and Fly In on the master slide.

The next example builds the placeholder hierarchy itself. It adds effects to a master placeholder, a layout placeholder, and the corresponding placeholder on a normal slide. Every call to IShape.GetBasePlaceholder is checked before the returned shape is used.

using System;
using Aspose.Slides;
using Aspose.Slides.Animation;
using Aspose.Slides.Export;

using var presentation = new Presentation();
var layoutSlide = presentation.LayoutSlides.GetByType(SlideLayoutType.Blank);
var layoutPlaceholder = layoutSlide.PlaceholderManager.AddTextPlaceholder(100, 100, 400, 80);
layoutSlide.Timeline.MainSequence.AddEffect(layoutPlaceholder, EffectType.Split, EffectSubtype.VerticalIn, EffectTriggerType.OnClick);

var masterPlaceholder = layoutPlaceholder.GetBasePlaceholder();
if (masterPlaceholder != null)
{
    var masterSequence = layoutSlide.MasterSlide.Timeline.MainSequence;
    masterSequence.AddEffect(masterPlaceholder, EffectType.Fly, EffectSubtype.Bottom, EffectTriggerType.OnClick);
}

var slide = presentation.Slides.AddEmptySlide(layoutSlide);
var slidePlaceholder = FindPlaceholderWithBase(slide);

if (slidePlaceholder == null)
{
    throw new InvalidOperationException("The slide does not contain a placeholder linked to its layout slide.");
}

slide.Timeline.MainSequence.AddEffect(slidePlaceholder, EffectType.RandomBars, EffectSubtype.Horizontal, EffectTriggerType.OnClick);
PrintEffects("Normal slide", slide.Timeline.MainSequence.GetEffectsByShape(slidePlaceholder));

var baseLayoutPlaceholder = slidePlaceholder.GetBasePlaceholder();
if (baseLayoutPlaceholder != null)
{
    PrintEffects("Layout slide", layoutSlide.Timeline.MainSequence.GetEffectsByShape(baseLayoutPlaceholder));

    var baseMasterPlaceholder = baseLayoutPlaceholder.GetBasePlaceholder();
    if (baseMasterPlaceholder != null)
    {
        PrintEffects("Master slide", layoutSlide.MasterSlide.Timeline.MainSequence.GetEffectsByShape(baseMasterPlaceholder));
    }
}

presentation.Save("placeholder-animations.pptx", SaveFormat.Pptx);

static IShape FindPlaceholderWithBase(ISlide slide)
{
    foreach (var shape in slide.Shapes)
    {
        if (shape.GetBasePlaceholder() != null)
        {
            return shape;
        }
    }

    return null;
}

static void PrintEffects(string source, IEffect[] effects)
{
    Console.WriteLine($"{source}: {effects.Length} effect(s)");

    foreach (var effect in effects)
    {
        Console.WriteLine($"  {effect.Type} {effect.Subtype}");
    }
}

Change Animation Timing

The PowerPoint Timing dialog maps to the properties of ITiming.

• Start maps to ITiming.TriggerType.
• Duration maps to ITiming.Duration, in seconds.
• Delay maps to ITiming.TriggerDelayTime, in seconds.
• Repeat maps to ITiming.RepeatCount, ITiming.RepeatUntilNextClick, or ITiming.RepeatUntilEndSlide.
• Rewind when done playing maps to ITiming.Rewind.

This independent example adds an effect, changes its timing through the object returned by ISequence.AddEffect, and saves the result. Keeping the returned IEffect reference avoids an unnecessary collection index.

using Aspose.Slides;
using Aspose.Slides.Animation;
using Aspose.Slides.Export;

using var presentation = new Presentation();
var slide = presentation.Slides[0];
var shape = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 120, 100, 320, 80);
shape.TextFrame.Text = "Timed animation";

var effect = slide.Timeline.MainSequence.AddEffect(shape, EffectType.Fade, EffectSubtype.None, EffectTriggerType.OnClick);
effect.Timing.TriggerType = EffectTriggerType.OnClick;
effect.Timing.Duration = 2.0f;
effect.Timing.TriggerDelayTime = 0.5f;
effect.Timing.RepeatUntilNextClick = false;
effect.Timing.RepeatUntilEndSlide = false;
effect.Timing.RepeatCount = 2.0f;
effect.Timing.Rewind = true;

presentation.Save("shape-animation-timing.pptx", SaveFormat.Pptx);

Use one repeat mode intentionally. Combining a repeat count with an “until” flag can produce confusing results in different viewers. When changing repeat modes, set ITiming.RepeatUntilNextClick and ITiming.RepeatUntilEndSlide before ITiming.RepeatCount, because setting either flag also changes the active repeat mode.

Add and Extract Animation Sounds

An animation effect can reference embedded audio through IEffect.Sound. IEffect.StopPreviousSound tells an effect to stop audio started by an earlier effect.

Add a Sound to an Effect

The following example expects a local audio file named animation-sound.wav. It creates two effects, embeds that file as the sound for the first effect, and configures the second effect to stop the sound. It uses the objects returned by ISequence.AddEffect, so no sequence index is required.

using System.IO;
using Aspose.Slides;
using Aspose.Slides.Animation;
using Aspose.Slides.Export;

using var presentation = new Presentation();
var slide = presentation.Slides[0];
var firstShape = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 80, 100, 240, 80);
var secondShape = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 400, 100, 240, 80);
firstShape.TextFrame.Text = "Starts sound";
secondShape.TextFrame.Text = "Stops sound";

var sequence = slide.Timeline.MainSequence;
var firstEffect = sequence.AddEffect(firstShape, EffectType.Fade, EffectSubtype.None, EffectTriggerType.OnClick);
var secondEffect = sequence.AddEffect(secondShape, EffectType.Fade, EffectSubtype.None, EffectTriggerType.OnClick);

var audioData = File.ReadAllBytes("animation-sound.wav");
var effectSound = presentation.Audios.AddAudio(audioData);
firstEffect.Sound = effectSound;
secondEffect.StopPreviousSound = true;

presentation.Save("shape-animation-sound.pptx", SaveFormat.Pptx);

Extract Embedded Effect Sounds

The following example expects a local presentation named presentation-with-animation-sounds.pptx. It scans both main and interactive sequences and writes every embedded effect sound to the extracted-animation-sounds directory. The extension is selected from the audio MIME type exposed by IAudio.ContentType.

using System;
using System.IO;
using Aspose.Slides;
using Aspose.Slides.Animation;

var inputPath = "presentation-with-animation-sounds.pptx";
var outputDirectory = "extracted-animation-sounds";

Directory.CreateDirectory(outputDirectory);

using var presentation = new Presentation(inputPath);
var soundIndex = 1;

foreach (var slide in presentation.Slides)
{
    SaveSounds(slide.Timeline.MainSequence, outputDirectory, ref soundIndex);

    foreach (var sequence in slide.Timeline.InteractiveSequences)
    {
        SaveSounds(sequence, outputDirectory, ref soundIndex);
    }
}

Console.WriteLine($"Extracted {soundIndex - 1} sound file(s) to {Path.GetFullPath(outputDirectory)}.");

static void SaveSounds(ISequence sequence, string outputDirectory, ref int soundIndex)
{
    foreach (var effect in sequence)
    {
        if (effect.Sound == null)
            continue;

        var extension = GetAudioExtension(effect.Sound.ContentType);
        var outputPath = Path.Combine(outputDirectory, $"effect-sound-{soundIndex}{extension}");
        File.WriteAllBytes(outputPath, effect.Sound.BinaryData);
        soundIndex++;
    }
}

static string GetAudioExtension(string contentType)
{
    var normalizedType = contentType == null ? string.Empty : contentType.ToLowerInvariant();

    if (normalizedType == "audio/mpeg")
        return ".mp3";

    if (normalizedType == "audio/mp4")
        return ".m4a";

    if (normalizedType == "audio/ogg")
        return ".ogg";

    if (normalizedType == "audio/wav" || normalizedType == "audio/x-wav")
        return ".wav";

    return ".bin";
}

For large audio objects, use IAudio.GetStream and copy the stream to a file instead of loading the entire object into a byte array.

Set After-Animation Behavior

The After animation option controls what happens to a shape after its effect finishes.

The AfterAnimationType enumeration supports leaving the shape unchanged, changing its color, hiding it after the animation, or hiding it on the next click. When the type is AfterAnimationType.Color, set IEffect.AfterAnimationColor as well.

This independent example creates an effect, sets its after-animation behavior through the returned effect object, and saves the result.

using System.Drawing;
using Aspose.Slides;
using Aspose.Slides.Animation;
using Aspose.Slides.Export;

using var presentation = new Presentation();
var slide = presentation.Slides[0];
var shape = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 120, 100, 320, 80);
shape.TextFrame.Text = "Dim after animation";

var effect = slide.Timeline.MainSequence.AddEffect(shape, EffectType.Fade, EffectSubtype.None, EffectTriggerType.OnClick);
effect.AfterAnimationType = AfterAnimationType.Color;
effect.AfterAnimationColor.Color = Color.LightGray;

presentation.Save("shape-animation-after-effect.pptx", SaveFormat.Pptx);

Changing the type away from AfterAnimationType.Color clears the after-animation color setting.

Animate Text

Text animation has two related controls:

• ITextAnimation.BuildType controls whether paragraphs appear together or by paragraph level.
• IEffect.AnimateTextType controls whether text appears all at once, by word, or by letter. IEffect.DelayBetweenTextParts sets the delay between words or letters. A positive value is a percentage of the effect duration; a negative value is a delay in seconds.

The following independent example animates the words in a text box. BuildType.AsOneObject disables paragraph-by-paragraph building so that the word setting applies to the entire text frame.

using Aspose.Slides;
using Aspose.Slides.Animation;
using Aspose.Slides.Export;

using var presentation = new Presentation();
var slide = presentation.Slides[0];
var textBox = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 80, 80, 560, 100);
textBox.TextFrame.Text = "Aspose.Slides animates this sentence word by word.";

var effect = slide.Timeline.MainSequence.AddEffect(textBox, EffectType.Fade, EffectSubtype.None, EffectTriggerType.OnClick);
effect.TextAnimation.BuildType = BuildType.AsOneObject;
effect.AnimateTextType = AnimateTextType.ByWord;
effect.DelayBetweenTextParts = 20.0f;

presentation.Save("animated-text.pptx", SaveFormat.Pptx);

To build a text box by paragraph, set BuildType.ByLevelParagraphs1 (or another paragraph level). To target a single paragraph with its own effect, use the ISequence.AddEffect overload that accepts an IParagraph. See Animated Text for paragraph-level examples.

Export and Compatibility Notes

• Saving to PPT or PPTX preserves the animation model, but the final playback is controlled by the presentation viewer.
• PDF and static images do not play animations. Use HTML5 export, animated GIF, or video conversion when the output must show motion.
• For HTML5, enable Html5Options.AnimateShapes and, when needed, Html5Options.AnimateTransitions.
• Video rendering supports many common entrance, emphasis, exit, and motion-path effects, but not every PowerPoint effect is supported. Check the current supported animations and effects and test critical presentations with your target Aspose.Slides version.
• Advanced custom effects and effects imported from other presentation formats may be preserved in the file but render differently in PowerPoint, HTML5, or video. Validate the exported result rather than relying only on the effect name.

FAQ

Why does an animation appear in PowerPoint but not in a PDF?

PDF is a static format, so animations and slide transitions do not play. Export to HTML5, animated GIF, or video when motion must be preserved.

Why does an effect play differently in a video?

Video export renders animations rather than storing the original PowerPoint behavior. Some advanced effects are unsupported or approximated. Review the supported-effects table and test the actual presentation before production use.

Does moving a shape forward or backward change its animation order?

No. Shape z-order controls overlap, while sequence order and triggers control animation playback. Change the timeline if you need a different playback order.

Related articles

• Animate PowerPoint Text in .NET